Spring darning attachment for sewing machines



March 6,1934. ALTHOFF 1,950,076

SPRING DARNING ATTACHMENT FOR SEWING MACHINES Filed June 25, 1932atented Mar. 5, 1934 UNiTEfi TATES PATENT OFFNE SPRING DARNINGATTACHMENT FOR SEWING VMACHINES 8 Claims.

The invention relates to attachments for sewing machines which willpermit the machine to be used for darning, braiding, embroidering andthe like, as well as for ordinary sewing.

5 Devices intended for this general purpose have been designed, but aregenerally of a complicated nature, or require special adjustments.Moreover, in all such devices known to me the attachment must be removedfrom the machine la in order to permit of ordinary sewing.

The primary object of the present invention is, therefore, to provide aninexpensive attachment which may be readily applied to the conventionalsewing machine for holding the presser bar thereof in such position thatdarning, em-

broidery and other special work may be done thereon, but which does nothave to be removed when doing plain sewing.

A further object of the invention is to provide an attachment which maybe applied to the conventional sewing machine without requiring themachine to undergo the slightest change (as for example changingtension, stitch, unscrewing parts, adjustment of the feed dog,

presser bar or thumb screw).

These objects are attained according to the preferred embodiment of myinvention by the use of a simple coil spring having rings, one at eachend thereof, for attachment with the presser bar and presser footlifting arm respectively. One ring of the attachment is first enagedover the presser bar leaving the spring hanging down, whereupon thelower ring is slid over the presser bar lifter. The tension of thespring ensures excellent work, and keeps the presser bar at the desiredheight, or close to the feed dog, when sewing or darning.

The attachment is simple in construction, cheap to manufacture, and isreadily applied and 40 detached.

' Other objects and advantages of the invention will be apparent duringthe course of the following description.

In the ccompanying drawing, forming a part 5 of this specification andin which like numerals are employed to designate like parts throughoutthe same,

Fig. 1 is a. side elevation view of the attachment applied to thepresser bar of a sewing n1achine, and

Fig. 2 is a view of the same looking from the end of the machine.

In the drawing, wherein for the purpose 01' illustration I have shown apreferred embodiment of my invention, the numeral 5 denotes the presserbar of a conventional sewing machine 6, having a presser foot 7 at itslower end and a lifting arm 8 for raising the presser bar, whichconstruction is common in the conventional type of treadle-operatedsewing machine. 50

Referring more particularly to my attachment, the device consists of anexpansible coil spring 9 having a ring 10 attached to each end thereof.'In applying the device to a sewing machine, the ring 10 at one end ofthe spring 9 is engaged over the upper end of the presser bar 5 and thespring expanded so as to permit the ring at the opposite end of thespring to be engaged over the lifting arm 8.

In operation, the presser foot 7 of the conventional sewing machine isnormally disposed in either an up or down position and is moved from oneposition to the other through operation of the lifting arm 8. In orderto perform darning or embroidery work on the conventional machine, it isnecessary for the presser foot 7 to be raised above the normal positionof the foot when doing plain sewing, and with my attachment applied tothe machine, it will be seen that the lifting arm 8 will be held in anyadjusted position, so that the presser foot may be elevated to thedesired degree. This adjustment may be accomplished by shifting thelower ring 10 along the lifting arm 8 tothe desired position. The ring10 will remain in whatever position it is placed 85. and the spring 9will exert a force the efiect of which will vary according to thedistance of the ring 10 from the fulcrum of the lifting arm 8.

By moving the ring 10 to the extreme right as indicated in dotted linesin Fig. 2 the sewing machine may be used for plain sewing withoutremoving the attachment from the lever arm. In the full line positionshown in Fig. 2 the ring 10 is applied at a substantial distance fromthe fulcrum of the lifting arm and the machine may 95, be used as adarner.

It is to be understood that the form of my invention herewith shown anddescribed is to be taken as a preferred example or the same and thatcertain changes in the shape, size and arrangement of the parts may bemade without departing from the spirit of the invention or the scope ofthe subjoined claims. For example, the rings 10 on the ends of the coilmay be changed for others of difierent size, in order that theattachment will better fit the various types of machines having longer,shorter, thicker or thinner presser bars. To this end the rings 10 aremade detachable. In this manner the same spring may be employed formachines of various 110 types, it being only necessary to providedifferent sized rings to suit varying requirements.

What I claim is:

1. An attachment for a conventional sewing machine of the type having apresser bar and presser foot lifting arm; comprising an expansiblespring coil having means at one end thereof adapted to be attached tothe upper end of the machine head and means at the other end for slidingattachment to the presser foot lifting arm, the spring being of suchlength and stiffness that it is maintained under sufficient tension whenthe attaching means are applied to the respective parts of the sewingmachine to hold the presser foot in any position above the work platewithout pulling it to the upward limit of its throw.

2. In a device of the character described, the combination with thepresser bar and lifting arm of a sewing machine, of a tension springhaving one end connected to the upper end of the presser bar and itsopposite end having a slidingly adjustable connection with the liftingarm, the spring being of such length and stiffness that it is maintainedunder sufficient tension to hold the presser foot in any position abovethe work plate without pulling it to the upward limit of its throw.

3. In a device of the character described, the combination with thepresser bar and lifting arm of a sewing machine, of a tension springhaving a ring at each end thereof adapted to be connected to the upperend of the presser bar and the lifting arm respectively, the springbeing of such length and stiffness that it is maintained undersufficient tension to hold the presser foot in any position above thework plate without pulling it to the upward limit of its throw.

4. A device as set forth in claim 3 in which the rings are detachableand are adapted to be replaced by others of different size to fitvarious types of presser bars.

5. In a device of the character described, the combination with thelifting arm of a sewing machine, of spring tension means adjustablyconnected at one end to the lifting arm for automatically varying thelifting effect according to the distance of the point of attachment fromthe fulcrum of the lifting arm, the spring being of such length andstiffness that it is maintained under sufficient tension to hold thepresser foot in any position above the work plate without pulling it tothe upward limit of its throw.

6. In a device of the character described, the combination with thelifting arm of a sewing machine, of a tension spring having one endattached to a fixed member at the upper portion of the machine, and itsopposite end adjustably connected to the lifting arm, whereby thelifting effect of the spring may be automatically varied according tothe distance of the point of attachment from the fulcrum of the liftingarm, the spring being of such length and stiffness that it is maintainedunder suflicient tension to hold the presser foot in any position abovethe Work plate without pulling it to the upward limit of its throw.

'7. In a device of the character described, the combination with thepresser bar and lifting arm of a sewing machine, of a tension springhaving one end connected to the upper end of the presser bar and itsopposite end adjustably connected to the lifting arm, the spring beingof such length and stiffness that it is maintained under sufficienttension to hold the presser foot in any position above the work platewithout pulling it to the upward limit of its throw.

8. An attachment for a conventional sewing machine of the type having apresser bar and presser foot lifting arm; comprising an expansiblespring coil having a ring at each end thereof adapted to be applied overthe upper end of the presser bar and over the presser foot lifting armrespectively, the spring being of such length and stiffness that it ismaintained under sufficient tension when the rings are applied to therespective parts of the sewing machine to hold the presser foot in anyposition above the work plate without pulling it to the upward limit ofits throw.

ANNY ALTHOFF.

